This invention pertains to a desuperheater header spray liner assembly used in high pressure steam boilers, and pertains particularly to an improved multiple support arrangement for such spray liner within the header.
Desuperheater header spray liners are usually provided in the headers of steam boilers to avoid erosion of the walls of the high pressure retaining header caused by injecting water into the desuperheater header. Such spray liners are usually rigidly attached to the header at one end and allowed to slide at the other end due to thermal expansion, with supports having close clearances being provided at selected points along the liner. However, it has been found that such supports are not only expensive to install properly, but can experience wear due to relative movement of the liner in the header. This can cause the liner to wear and loosen, vibrate, and eventually fail due to fatigue. Such liner failures necessitate boiler shutdown and expensive outage and repairs. For this reason, improvements are greatly needed in such desuperheater spray liners, especially in their support arrangements and configuration to lessen or eliminate wear and also to minmize or avoid welding of dissimilar materials.